Field of the Disclosure
This disclosure pertains generally to power supplies and more specifically to compactness of power supply controllers.
Description of the Related Art
The compactness and efficiency of power supplies is an increasing concern to users and manufacturers of electronics. Switching power supplies with pulse width and pulse frequency modulated controllers offer both compactness and efficiency in a number of different topologies. Switching power supply controllers are available in a single integrated circuit chip or package having some number of external connection pins or terminals. As with many other types of integrated circuit chips or packages, limiting the number of external connection terminals of a power supply package is advantageous, allowing both a reduced form factor and over-all cost.
However, as the complexity of electronic devices is increasing, the complexity of power supply specifications is also increasing. It is often required for a power supply to operate in a number of different operational modes based on many different factors. Therefore, it is desirable to provide configurability of the power supply to achieve a desired outcome by the system designer. In order to address this requirement, switching power supply controllers have incorporated multiple features and operating modes, which can be enabled and configured by a power supply designer. Exemplary features and operating modes include over-temperature, over-voltage, and over-current protection modes. Multiple modulation modes may also be enabled, which impact output characteristics (such as output ripple and output regulation) as well as input characteristics (such as power factor correction). Unfortunately, the goal of providing compact and low cost power supply solutions is often at odds with the goal of maximizing power supply functionality and performance. Accordingly, it is desirable to provide a compact and low cost power supply that enables a wide range of programmable features and operating modes.